Prehistoric Creatures

Prehistoric Creatures of Planet Earth

The title sounds like a Science Fiction ‘B’ movie. But the reality is giant monsters and ancient beasts lived in the seas, on land and in the skies of a prehistoric world we call home. Here are some fun facts about some of the more popular Ancient Mammals, Ornithischians, Pterosaurs, Sauropods and Theropods.

Artwork and essay by Joe Tucciarone

Ancient Mammals

Glyptodon

The now extinct Doedicurus lived during the Pleistocene epoch and was a member of the family Glyptodontidae. Unlike its modern cousin, the armadillo, Doedicurus was a giant creature more than a dozen feet long!
Name: Doedicurus
Length: 13 feet
Weight: up to 2 tons
Time: 1.8 million to 11,000 years ago (Pleistocene epoch)
Place: South America
Diet: plant-eater (herbivore)

Hyracotherium

The ancestor of the modern horse, first appeared in the early Eocene epoch in the forests of North America. Also known as Eohippus, the "Dawn Horse", it was the size of a small dog. Unlike horses today, this primitive horse had several toes on each foot.
Name: Hyracotherium
Length: 2 feet
Weight: 15 pounds
Time: about 50 million years ago (early Eocene)
Place: North America
Diet: plant-eater (herbivore)

Smilodon

This extinct cat, also known as the Sabertooth Cat, had a short tail, strong front legs and canine teeth up to seven inches long. These characteristics and others indicate that it ambushed prey animals rather than chasing them down.
Name: Sabertooth Cat (Smilodon fatalis)
Length: 8-9 feet
Weight: 400-500 pounds
Time: 1.8 million to 11,000 years ago (Pleistocene epoch)
Place: North America
Diet: meat-eater (carnivore)

Uintatherium

This beast was one of the many bizarre mammals roaming North America during the late Eocene epoch. This bulky, hoofed animal was larger than a modern rhinoceros and sported an array of short, knobby horns which grew upward from its nasal bones. In addition, a pair of daggerlike canine tusks jutted downward from its upper jaw. Uintatherium was an ancient, distant cousin of horses, elephants and whales.
Name: Uintatherium
Length: 10-15 feet
Weight: 5,000-6,000 pounds
Time: Late Eocene
Place: Asia, North America
Diet: Plant-eater (herbivore)

Woolly Mammoth

The woolly mammoth was bigger than its modern elephant relatives and was the largest land animal alive during the late Pleistocene epoch. Their closest living relatives are the Indian elephants.
Name: Woolly Mammoth
Type Species: * Mammuthus primigenius
Height: 9-12 feet tall at the shoulder
Weight: 7-8 tons
Time: 120,000-4,000 years ago (Late Pleistocene)
Place: Northern Europe, Siberia, North America
Diet: Plant-eater (herbivore)

Woolly Rhino

The Woolly Rhinoceros lived on the tundra of Europe and Asia during the Pleistocene epoch. This Ice Age mammal may have survived until as recently as 20,000 years ago.
Name: Woolly Rhinoceros
Length: 10-12 feet
Weight: 2-3 tons
Time: 200,000 to 20,000 years ago (Pleistocene epoch)
Place: Northern Europe, Siberia
Diet: plant-eater (herbivore)

Almost everybody's favorite dinosaurs were colossal animals like Triceratops or Apatosaurus, yet not all of the dinosaurs were so gigantic. Microceratops was a distant relative of lumbering Triceratops and massive Styracosaurus, but it was only the size of a rabbit.
Name: Microceratops ("small horns face"; Bohlin, 1953)
Length: 2 feet (0.6 meter)
Weight: 8-15 pounds
Time: 80-65 million years ago (Late Cretaceous)
Place: China, Mongolia
Diet: plant-eater (herbivore)

The double row of bony plates on its back and the cluster of dangerous spikes on its tail made Stegosaurus one of the most distinctive and well-armed creatures that has ever walked the earth.
Genus Name: Stegosaurus ("roofed lizard")
Type Species: * S. armatus (Marsh, 1877)
Length: 25-40 feet (8-12 meters)
Weight: 4-7 tons
Time: 160-145 million years ago (Late Jurassic)
Place: Colorado, Utah, Wyoming
Diet: plant-eater (herbivore)

Stygimoloch

Stygimoloch was a small pachycephalosaur whose thick skull bristled with bony knobs and spikes. It may have engaged in head-butting, either for defense or to establish a pecking order during mating. Its name derives from the river Styx ("stygi") and the name of a Semitic god, Moloch. In Greek mythology, the Styx was a mythical river flowing through the underworld near Hades (Hell). Stygimoloch's remains were discovered in the Hell Creek formation of Montana and Wyoming. According to myth, children were fed to the god Moloch. However, even if there had been any youngsters around in the Cretaceous, they would have been in no danger of being eaten by Stygimoloch; it was a vegetarian.
Genus Name: Stygimoloch (River "Styx" and Semitic
god, "Moloch")
Type Species: * S. spinifer (Galton & Sues, 1983)
Length: 6-9 feet (2-3 meters)
Weight: 150-220 pounds
Time: 74-65 million years ago (Late Cretaceous)
Place: Montana, Wyoming
Diet: plant-eater (herbivore)

Thescelosaurus was a small dinosaur living near the end of the Age of Dinosaurs. Its run-of-the-mill appearance assured it a position of relative obscurity until a specimen nicknamed "Willo" brought the genus to prominence. Preserved in the stone within Willo's chest cavity is a feature some scientists have interpreted as the imprint of a four-chambered heart. Since birds and mammals also have four-chambered hearts this discovery, if confirmed, would support the view of dinosaurs as active, warm-blooded creatures.
In hindsight, the decades-old name of this animal may be appropriate: Thescelosaurus, (Greek theskelos="marvelous", sauros="lizard") the Marvelous Lizard!
Genus Name: Thescelosaurus ("wonderful lizard")
Type Species: * T. neglectus (Gilmore, 1913)
Length: 13 feet (4 meters)
Weight: 1/3 ton
Time: 72-66 million years ago (Late Cretaceous)
Place: Colorado, Montana, S. Dakota, Wyoming,
Alberta, Saskatchewan
Diet: plant-eater (herbivore)

Triceratops

The huge head of this prehistoric beast was adorned with three horns and a clashing beak, and a large bony frill shielded the animal's neck. The horns may have been a defense against predatory dinosaurs, but like the antlers of a deer they may also have been used to battle rivals for mates or territory.
Genus Name: Triceratops ("three horns face")
Type Species: * T. horridus (Marsh, 1889)
Length: 26-33 feet (8-10 meters)
Weight: 5-9 tons
Time: 72-65 million years ago (Late Cretaceous)
Place: Colorado, Montana, S. Dakota, Wyoming, Alberta, Saskatchewan
Diet: plant-eater (herbivore)

Pterosaurs: Winged Reptiles

Cearadactylus

This was a large pterosaur from the Santana Formation in northeastern Brazil. Its kinked upper jaw is reminiscent of the upper jaw of Spinosaurus, a very large dinosaur thought to have subsisted on a diet of fish. Cearadactylus' long front teeth probably enabled it to catch and hold slippery fish.
Genus Name: Cearadactylus ("Ceara finger")
Type Species: * C. atrox (Leonardi, G. and Borgomanero, G., 1985)
Wingspan: up to 18 feet (5.5 meters)
Weight: 30 pounds
Time: 115 million years ago (Early Cretaceous)
Place: Brazil (Araripe Plateau)
Diet: meat-eater (carnivore)

Pteranodon

Not all of the reptiles living in the Mesozoic Era were dinosaurs. The pterosaurs were a diverse group of flying reptiles found all over the earth during the reign of the dinosaurs. Pteranodon was a large pterosaur with a wingspan well over twenty feet. The fur which covered some pterosaurs indicates they may have been warm-blooded, a trait shared by birds and mammals.
Genus Name: Pteranodon ("toothless flier")
Type Species: * P. longiceps (Marsh, 1876)
Wingspan: up to 23 feet (7 meters)
Weight: 35-50 pounds
Time: 65 million years ago (Late Cretaceous)
Place: Kansas (USA) and England
Diet: meat-eater (carnivore)

One of the largest creatures ever to fly was a pterosaur known as Quetzalcoatlus, which had an immense wingspan equalling that of a twin engine jet fighter.
Name: Quetzalcoatlus (Named for the feathered Aztec god, "Quetzalcoatl"; D. A. Lawson, 1971)
Wingspan: up to 36 feet (11 meters)
Weight: 200-300 pounds
Time: 75-65 million years ago (Late Cretaceous)
Place: Texas (Big Bend National Park)
Diet: meat-eater (carnivore)

Tapejara

This unusual pterosaur was found in the Santana Formation in Brazil. The prominent facial crests may have been used for display during the mating season, and the toothless beak indicates it may have subsisted on carrion. It's name "Tapejara" means "The Old Being" and derives from the Tupi Indians, who were the original inhabitants of the region.
Genus Name: Tapejara ("The Old Being")
Type Species: * T. wellnhoferi (Kellner, 1989)
Wingspan: 10 to 16 feet? (3 to 5 meters?)
Weight: 10 to 25 pounds?
Time: about 115 million years ago (Early Cretaceous)
Place: Brazil (Araripe Plateau)
Diet: meat-eater (carnivore)

Tropeognathus

Although true birds existed during the latter half of the Age of the Dinosaurs, the real masters of those ancient skies were the pterosaurs. This large pterosaur, known as Tropeognathus, soared through the skies over what is now Brazil on wings spanning twenty feet. Its oddly crested snout and toothy jaws were well suited for grasping fish as it skimmed along the surface of the water.
Genus Name: Tropeognathus ("Keel jaw")
Type Species: * T. mesembrinus, T. robustus
Wingspan: up to 20 feet (6.5 meters)
Weight: 30 pounds
Time: 115 million years ago (Early Cretaceous)
Place: Brazil (Araripe Plateau)
Diet: meat-eater (carnivore)

Sauropod Dinosaurs

Alamosaurus

Thirty million years after sauropod dinosaurs had become extinct in what is now North America, the sauropod Alamosaurus reappeared there. Paleontologists believe their ancestors may have migrated from South America across a new land bridge that joined the two continents.
Name: Alamosaurus ("Alamo lizard")
Length: 69 feet (21 meters)
Weight: 30-33 tons
Time: 74-65 million years ago (Late Cretaceous)
Place: New Mexico, Texas, Utah
Diet: plant-eater (herbivore)

The heavyweight champion of the dinosaurs may have been a sauropod discovered in South America called Argentinosaurus. This behemoth was over a hundred feet long and weighed nearly one hundred tons. Argentinosaurus was a member of a family of Cretaceous Period sauropods which are fittingly called "titanosaurs".
Genus Name: Argentinosaurus ("Argentina lizard")
Type Species: * A. huinculensis (Bonaparte & Coria, 1993)
Length: about 130 feet (40 meters)
Weight: up to 100 tons
Time: Late Cretaceous
Place: Argentina
Diet: plant-eater (herbivore)

Brachiosaurus

Weighing almost seventy tons, Brachiosaurus was one of the biggest land animals that has ever lived. Since its front legs were longer than its hind legs, Brachiosaurus had a more upright stance than most sauropods. This dinosaur could raise its head almost forty feet off the ground to graze high in the trees and must have looked like a titanic, reptilian giraffe. However, since Brachiosaurus lived over one hundred million years before the first giraffe appeared, it may be more appropriate to say that giraffes are tiny, mammalian versions of the Brachiosaurs!
The figure of a six-foot tall man helps illustrate how immense this creature was.
Genus Name: Brachiosaurus ("arm lizard")
Type Species: * B. altithorax (Riggs, 1903)
Length: 65-90 feet (20-27 meters)
Weight: 30-70 tons
Time: 155-150 million years ago (Late Jurassic)
Place: Utah, Colorado, Portugal, Tanzania
Diet: plant-eater (herbivore)

Seismosaurus

This big guy may not have been the heaviest dinosaur, but it was certainly one of the longest land animals that has ever lived. It stretched almost one hundred and fifty feet from tail-tip to snout and weighed almost as much as fifteen full-grown African elephants. Surely this creature shook the earth as it lumbered across the ancient terrain.
Genus Name: Seismosaurus ("earth shaker lizard")
Type Species: * S. hallorum (Gillette, 1991)
Length: about 150 feet (45 meters)
Weight: 30-70 tons
Time: 155-145 million years ago (Late Jurassic)
Place: New Mexico
Diet: plant-eater (herbivore)

Theropod Dinosaurs

Allosaurus

Allosaurus was the biggest carnivorous dinosaur of the Jurassic period. No other predatory dinosaur had ever grown so large and none would surpass it in size for fifty million years.
A fossil find in Utah has raised the possibility that Allosaurus was a pack hunter.
Genus Name: Allosaurus ("different lizard")
Type Species: * A. fragilis (Marsh, 1877)
Length: up to 38 feet (12 meters)
Weight: 1-3 tons
Time: 150-145 million years ago (Late Jurassic)
Place: Colorado, Montana, New Mexico, Oklahoma,
S. Dakota, Utah, Wyoming, Portugal
Diet: meat-eater (carnivore)

Archaeopteryx

This was one of the earliest known birds, living among the dinosaurs of the Jurassic period about one hundred and fifty million years ago. This small creature represents evolution 'caught in the act', having birdlike features (feathers) and reptilian traits (teeth and a bony tail).
Genus Name: Archaeopteryx ("ancient wing/feather")
Type Species: * A. lithographica (von Meyer, 1861)
Length: 1.5 feet (0.45 meter)
Weight: less than one pound (300-450 grams)
Time: 150 million years ago (Late Jurassic)
Place: Germany
Diet: meat-eater (carnivore)

Ceratosaurus

Ceratosaurus was a primitive theropod dinosaur prowling what are now the states of Utah and Colorado during the Late Jurassic period. It's most distinctive features were its prominent nose and eye horns. Ceratosaurus also had four-fingered "hands", unlike the (three-fingered) allosaurs with which it competed for prey.
Genus Name: Ceratosaurus ("horned lizard")
Type Species: * C. nasicornis (Marsh, 1884)
Length: 15-20 feet (4.5-6 meters)
Weight: 0.5-1 ton
Time: 156-145 million years ago (Late Jurassic)
Place: Colorado, Utah
Diet: meat-eater (carnivore)

It has been many ages since the last of the dinosaurs walked the earth. Sixty-five million years have passed since they became extinct, yet that is a brief time compared to their long reign. Coelophysis was an early predatory dinosaur of the Late Triassic period. It lived so long ago that more than twice as much time separates it from the tyrannosaurs as that which separates the tyrannosaurs from us.
Genus Name: Coelophysis ("hollow form")
Type Species: * C. bauri (Cope & Colbert, 1964)
Length: 8-10 feet (2.5-3 meters)
Weight: 25-70 pounds
Time: 222-215 million years ago (Late Triassic)
Place: Arizona, New Mexico
Diet: meat-eater (carnivore)

Compsognathus

Compsognathus was one of the smallest of the dinosaurs. A full-grown adult would have weighed no more than a turkey.
The slender build of this dinosaur indicates it was a fast and agile creature. Studies suggest it may have been able to run at a speed of 40 miles per hour.
Genus Name: Compsognathus ("elegant jaw")
Type Species: * C. longipes (Wagner, 1859)
Length: 24-49 inches (60-125 centimeters)
Weight: 5-10 pounds
Time: 150 million years ago (Late Jurassic)
Place: France, Germany
Diet: meat-eater (carnivore)

Dilophosaurus was one of the first large predatory dinosaurs on earth. Although this creature was almost twenty feet long it was slender in build and weighed less than half of a ton. A crest over each eye projected at an angle from the animal's forehead. These delicate crests were too fragile to withstand much abuse and were probably used for display.
Genus Name: Dilophosaurus ("double-crested lizard")
Type Species: * D. wetherilli (Welles, 1954)
Length: 20 feet (6 meters)
Weight: 700-1,000 pounds
Time: 200-190 million years ago (Early Jurassic)
Place: Arizona, China
Diet: meat-eater (carnivore)

Giganotosaurus

Giganotosaurus may have been the largest and most massive predatory dinosaur that ever lived. The biggest giganotosaur was a yard longer and a ton heavier than "Sue", the largest known Tyrannosaurus rex. Despite a resemblance to the more famous tyrannosaurs, anatomical features of Giganotosaurus show it was a member of the Allosaurus clan.
Genus Name: Giganotosaurus ("giant southern lizard")
Type Species: * G. carolinii (Coria & Salgado, 1995)
Length: 42-46 feet (12.8-14 meters)
Weight: 8 tons
Time: 100 million years ago (Early Cretaceous)
Place: Argentina
Diet: meat-eater (carnivore)

Oviraptor

Several skeletons of this small dinosaur have been found associated with nests containing eggs, which they were presumably incubating or protecting. The feathers on the arms in this depiction are speculative and are based on the animal's lineage. Oviraptor belongs to the "Maniraptora", a group of birdlike dinosaurs that includes some types which are known to have been feathered. In any case, this coelurosaurian dinosaur was quick-footed and had a relatively large brain within its crested skull. Its highly specialized jaws imply a diet which may have included eggs, shellfish and even vegetation.
Genus Name: Oviraptor ("egg raider")
Type Species: * O. philoceratops (Osborn, 1924)
Length: 6 feet (2 meters)
Weight: 20 - 35 kilograms
Time: 72 million years ago (Late Cretaceous)
Place: Mongolia
Diet: meat and plant-eater (omnivore)

Spinosaurus

It had a body like that of a lean tyrannosaur, a head like that of a titanic crocodile and a sail on its back like that of a mythical dragon! The teeth of this carnivore were also unusual. Unlike most other big meat-eaters, Spinosaurus had straight, conical teeth that indicate it dined mostly on fish! This healthy diet helped Spinosaurus become one of the longest known theropods in dinosaur history.
Genus Name: Spinosaurus ("spine lizard")
Type Species: * S. aegyptiacus (Stromer, 1915)
Length: 39-49 feet (12-15 meters)
Weight: 2-4 tons
Time: 110-98 million years ago (Middle Cretaceous)
Place: Egypt, Morocco
Diet: meat-eater (carnivore)

The word "bizarre" is often used to describe dinosaurs, but few of them were as strange as Therizinosaurus. It had the long neck, small head and tiny, leaf-shaped teeth of a sauropod. However, it wasn't a sauropod; it was a plant-eating theropod! This dinosaur had other strange features, including a broad potbelly and incredibly long finger claws. Most paleontologists believe Therizinosaurus was the reptilian analog of the giant (extinct) ground sloth, and those huge claws were probably used to pull leafy branches close to its mouth.
Genus Name: Therizinosaurus ("scythe lizard")
Type Species: * T. cheloniformis (Maleev, 1954)
Length: 23-33 feet (7-10 meters)
Weight: 2-3 tons
Time: 70 million years ago (Late Cretaceous)
Place: Mongolia, Kazakhstan and Transbaykalia
Diet: plant-eater (herbivore)

Troodon

Troodon was a small but deadly hunter. Unlike most dinosaurs, its big eyes faced partly forward, probably giving Troodon the same kind of binocular vision used by modern predators like cats. Opposable fingers enabled it to grasp its prey, something few other dinosaurs could do. The second toe on each foot had a large slashing claw like those carried by raptors. Finally, the ratio of its brain weight to its body weight was greater than that of almost any other dinosaur.
Genus Name: Troodon ("wounding tooth")
Type Species: * T. formosus (Leidy, 1856)
Length: 2 meters
Weight: 100-125 pounds
Time: Late Cretaceous
Place: Canada, Mexico, United States, Tadzhikistan, Uzbekistan
Diet: meat-eater (carnivore)

Tyrannosaurus Rex

Tyrannosaurus Rex: A full-grown Tyrannosaurus rex stood fifteen feet tall and was nearly twice as heavy as a bull elephant. It possessed one of the largest brains ever evolved in the animal kingdom, even larger than those of most mammals that have ever lived. That magnificent brain was the engine powering one of the most ferocious carnivores of all time.
Keen eyes glared from its massive head, and when those cavernous jaws opened wide they revealed dangerous rows of eight-inch teeth. Tyrannosaurus rex was truly the King of the Dinosaurs!
Genus Name: Tyrannosaurus ("tyrant lizard")
Type Species: * T. rex (Osborn, 1905)
Length: up to 42 feet (12.8 meters)
Weight: 5-7 tons
Time: 67-65 million years ago (Late Cretaceous)
Place: Alberta, Saskatchewan, Colorado, Montana, New Mexico, N. Dakota, S. Dakota, Wyoming
Diet: meat-eater (carnivore)

Utahraptor

Because of the "killer claws" on their feet, the dromaeosaurs (popularly known as "raptors") are thought to have been an extremely lethal group of dinosaurs. Well-known members of this dangerous clan include Velociraptor and Deinonychus. However, towering over all of them was Utahraptor, which is the largest confirmed dromaeosaurid dinosaur.
Genus Name: Utahraptor ("utah raider")
Type Species: * U. ostrommaysorum (Kirkland, Gaston & Burge, 1993)
Length: 15-23 feet (5-7 meters)
Weight: 1 ton
Time: 120 million years ago (Early Cretaceous)
Place: Utah
Diet: meat-eater (carnivore)

Velociraptor

It was a small, slender dinosaur that stood just three feet tall and weighed as much as an average dog. However, it had lethal claws and one of the highest brain-to-body weight ratios of any dinosaur. These and other features of its skeletal remains show it was an agile and aggressive predator.
Genus Name: Velociraptor ("speedy raider")
Type Species: * V. mongoliensis (Osborn, 1924)
Length: 6.5 feet (2 meters)
Weight: 15-33 pounds (7-15 kilograms)
Time: 85 million years ago (Late Cretaceous)
Place: China and Mongolia
Diet: meat-eater (carnivore)

Amazing Prehistoric Creatures of the Planet Earth

If you are into prehistoric creatures like dinosaurs and other animals that have gone extinct thousands and even millions of years ago, you should check out this website where you can find out everything you want to know about your favorite dinosaur and other prehistoric animals. You will be amazed at how these animals looked and lived. You would think that they are just a figment of someone’s imagination but they roamed the earth way before the first human was born.

Below is a list of random facts about some of the most popular prehistoric creatures.

Smilodon. Or more popularly known as the Sabertooth Cat, was known for its canine teeth that can grow up to seven inches long. This characteristic implies that the animal ambushed rather than chased its prey.

Woolly mammoth. Another popular prehistoric animal is the woolly mammoth. It was bigger than its cousin, the modern-day elephant. These herbivores thrived in Northern Europe, North America, and Siberia.

Woolly rhino. These are not as popular as the woolly elephant but woolly rhinos also existed around the same epoch as woolly elephants. This Ice Age animal lived on the tundra of Asia and Europe.

Stegosaurus. The dangerous spikes on its tail and the double rows of bony plates on its back made this dinosaur one of the most well-armed dinosaurs on earth. Its distinctive physical characteristics also made it well-known in popular culture.

Triceratops. Known for the three prominent horns on its head, the triceratops are also one of the most popular dinosaurs in movies and story books. They lived about 72 to 65 million years ago in some parts of North America.

Pteranodon. This large winged reptile had a wingspan of over 20 feet. Its body was covered by fur, which indicates that pteranodon was warm-blooded and not cold-blooded like other reptiles.

Apatosaurus. This large dinosaur is probably the most favorite. It was formerly known as Brontosaurus and lived in the Jurassic era.

Brachiosaurus. Considered as one of the biggest and heaviest animals that lived on earth, this reptile weighed 70 tons! The modern-day giraffe is associated with this dinosaur.

Tyrannosaurus Rex. This list will not be complete without one of the most ferocious predator of all time, the T.Rex. It possessed a large brain, larger that most animals in the animal kingdom.

These are just some of the most popular prehistoric creatures that lived on planet earth. There’s still plenty of others that lived in different epochs so be sure to find out more about these ancient creatures.